On any other day a visit by the Hoops to the Nou Camp would signal little more than a training run for the European giants.

However, having watched Neil Lennon’s side shock 3-2 triumph at Spartak Moscow in their last Group G outing Alba insists Celtic are no joke and has his team wary of a massive upset.

The Catalans battled to beat the Russians in their Champions League opener last month and the Spanish star insists the Barca boys will need to be at their best if they’re to claim the vital three points.

“We know it won’t be easy against Celtic because we have already suffered at home against Spartak when they came close to winning,” left-back Alba said.

“We don’t want to repeat the experience against the Scots. We know if we can get the six points in these next two games against Celtic, it will secure our passage into the next round.

“Of course, we’re big favourites in this group and we’re prepared for that role. It doesn’t affect our performance but it does increase the effort of our rivals.”

Not only will Celtic be buoyed by their recent European success - the Scottish Champions have four points from two fixtures - they’re also coming off a 5-0 victory over St Mirren.

Barca, meanwhile, leaked four goals in Saturday’s La Liga win over Deportivo La Coruna, and Alba added: “Everyone knows Spanish football is superior to Scottish football but we respect Celtic.

“I didn’t expect Celtic’s win in Russia but that has given them belief they can also qualify.

“That is a warning to us not to be too confident. We have watched some of Celtic’s games already and they are a good team, who are always looking to exploit mistakes and take their chances.”

And Celtic certainly aren’t heading to Catalunya just to stand back and marvel at their star-studded opponents, with Lennon insisting his side will take the fight to Lionel Messi and Co.

“It will be awesome if we can get something out of the match but it won’t be great if we lose the game,” the manager said.

“We are not going to get carried away by the surroundings, that is for the supporters. The players have to go there and compete and do themselves justice.

“We had the [Champions League] qualifiers which was our short term aim but now we are in there the players are believing that they are good enough to play at that level.”